My invention pertains to a shelf mount for a plug-in type relay. More particularly, the invention relates to shelf mounting apparatus, including vibration cushioning and access openings, for vital plug-in type relays normally wall mounted.
Historically, in the railroad signaling field, the vital relays necessary for the operation of signal systems were shock mounted on the shelves within signal equipment houses and cases. Subsequently, wall mounted plug-in style vital relays were developed to allow quick, easy, and error free replacement of relays to permit change out, inspection, repair, and readjustment of vital relays without involving the error-prone process of individually disconnecting and reconnecting all the wire leads to the relay. Since their introduction, the use of plug-in vital relays has increased until they have very nearly supplanted the equivalent shelf mounted relays. To some degree, it is becoming uneconomical to continue manufacturing all possible models of shelf relays. However, applications remain where the shelf mounting of relays is still desirable, e.g., the individual replacement of shelf relays in an existing installation. A mounting arrangement which allows the use of modern plug-in type relays as a shelf relay, with a plug-in connector, provides distinct advantages and is therefore desirable.
Accordingly, an object of my invention is a mounting base with vibration cushioning whereby a plug-in relay may be used in a shelf mounted configuration.
A further object of my invention is a shelf mounting arrangement for a plug-in relay which provides access for relay adjustment and visual inspection of contacts and operation.
Yet another object of the invention is mounting apparatus by which plug-in relays may be shelf mounted, with vibration and shock damping and openings for access to calibration adjustments and for visual inspection of relay contacts and operation.
A still further object of my invention is shelf mounting apparatus for a plug-in type relay including a molded holder element, to cradle the relay in normal operating position, mounted on a shelf with vibration damping and shock isolation to protect the relay from damage and inhibit false operation and with access openings for calibration adjustment, visual inspection, and plug coupler connections of leads.
Other objects, features, and advantages of the invention will become apparent from the following specification and appended claims when taken with the accompanying drawings.